It is known, for example, for a lens-equipped film that an image such as photograph, character, or letter is subjected to preexposure beforehand as a latent image on the film. This procedure is performed in order to prepare a photograph on which the preexposed image is combined with a part of a subject to be photographed with the lens-equipped film.
A variety of suggestions have been hitherto made concerning such a technique. Those known include, for example, a "preexposure method for photographic films" disclosed in Japanese Laid-Open Patent Publication No. 9-230448. In this conventional technique, at first, an aligned film strip is installed to a single use camera on which a shield mask is placed corresponding to an illustration portion. Exposure is performed by using the single use camera followed by development to form, on the aligned film strip, a transparent area corresponding to the shield portion of the shield mask and an opaque portion corresponding to the open portion.
Subsequently, the aligned film strip is charged in a copy camera. The illustration is arranged so that the illustration may be viewed through the transparent area. A photographing film strip is installed in the copy camera to photograph the illustration, followed by applying a development treatment. Thus, a manuscript film strip is obtained.
An unexposed film strip, which is charged on a film strip supply reel, is moved through a slot onto a winding reel. The slot comprises a contact base plate and an exposure plate. The unexposed film strip and the photographing film strip pass therethrough while allowing their surfaces to make contact with each other. During this process, a light source is turned on in a throttle. An image on the photographing film strip is recorded (subjected to preexposure) as a latent image on the unexposed film strip.
The conventional technique described above requires the operation to previously charge the unexposed film strip on the supply reel. Another operation is performed such that the unexposed film strip, which is fed from the supply reel, is wound around a winding reel, and then the unexposed film strip is wound and accommodated in a shield container such as a film cartridge or Patrone.
Therefore, dominant parts of the operation for forming the latent image on the unexposed film strip are performed manually. A problem is pointed out that it is not easy to realize the efficient entire operation and perform the operation automatically. Especially, in the case of the steps in which a large amount of lens-equipped films are produced, a considerable period of time is required for the preexposure operation, resulting in such an inconvenience that it is impossible to achieve any efficient operation for producing the lens-equipped film.
In the conventional technique described above, when the photographing film strip is prepared, the operation is performed to expose the photographing film strip with the illustration by photographing the illustration as an image for preexposure by using the copy camera. For this reason, a problem is pointed out that the entire operation for producing the photographing film strip is complicated and time-consuming.
In the conventional technique described above, the manuscript film strip is used to expose one unexposed film strip. For example, the film strip has twenty-four frames, and the manuscript is constructed to have a loop-shaped configuration (loop manuscript). The loop manuscript is placed with the film strip in the slot with their surfaces contacted with each other. In this state, the light source is turned on in the throttle, and thus the latent image is recorded on the unexposed film strip.
However, the loop manuscript is set to have a length corresponding to one individual of the unexposed film strip. Therefore, the loop manuscript contacts with the unexposed film strip for every one individual of the unexposed film strip. As a result, the following problems are pointed out. That is, the dust or the like tends to adhere to the loop manuscript with ease, the damage is apt to occur, and the durability is deteriorated.
Further, it is necessary to perform the position adjustment between the forward end of the loop manuscript and the unexposed film strip before starting the preexposure. It is required that the position adjustment operation is performed for even one individual of the unexposed film strip. For this reason, a problem arises that it is difficult to perform the preexposure treatment for the unexposed film strip continuously at a high speed.
The present invention has been made in order to solve such problems, an object of which is to provide a preexposure method and a preexposure apparatus for photosensitive films, which make it possible to preexpose the film with a desired image quickly and reliably, and achieve the entire automatic and efficient preexposure operation.
Another object of the present invention is to provide a preexposure method and a preexposure apparatus for photosensitive films, which make it possible to efficiently record, on a preexposure manuscript, a high quality image for performing preexposure on a film, and perform the preexposure operation highly accurately.